Governor for fluid-actuated rotary tools



Sept. 2, 1924. 1506,8632

I F. w. PARSONS GOVERNOR FOR FLUID ACTUATED ROTARY TOOLS Filed Sept. 51921 3 Sheets-Sheet 2 INVENTOR fiedeeivkw amans Sept. 2 1924. 1,506,862

' F. w. RsoN GOVERNOR FOR FLUID AGTUATED ROTARY TOOLS Filed Sept. 5.1921 s Sheets-Sheet cs 9 10; k7 r a E i INVENTOR 17 m??? l L l amo'lzsPatented Sept. 2, I924.

UNITED STATES I 1,506,862 PATENT OFFICEL FREDERICK PARSONS, F ELMIRA,NEW YORK, ASSIGNOR TO INGERSOLL-RAND COMPANY, OF JERSEY CITY, NEWJERSEY, A CORPORATION OF NEW JERSEY.

GOVERNOR FOR FLUID-ACTUATED RO'TARY TOOLS.

Application filed September 8, 19.21. Serial No. 498,581.

Tooll whom it may concem:

Be it known that I, FREDERICK WV. PAR- SONS, a citizen of the UnitedStates, and a resident of Elmira, county of Che-mung, 5 State of NewYork, have invented a certain Governor for Fluid-Actuated Rotary Tools,

of which the following is a specification accompanied by drawings. r

This invention relates to fluid actuated rotary tools, such as drillsfor example, of the type adapted to be driven by a fluid actuated rotarymotor. A pneumatic tool of this type may be used for drilling, reaming,tapping, flue rolling, wood boring, stud setting, bolt tightening,running down screw spikes,

setting valves and for various other wellknown uses.

In drilling or reaming for instance, as well as in other cases,excessive wear on the parts has occurred, and damage has sometimes beendone to the tool, due to overspeeding and racing, when the resistance torotationhas been materially decreased or suddenly removed, as when thedrill bit or reamer is lifted from the hole being drilled or reamed,with full supply of fluid pressure su plied to the tool.

uchtools are conveniently driven by compressed air, but manual controlhas usually been depended upon for regulating the machine and theoperator may not control-the air at the main throttle quickly enough toprevent over-speeding and damage to the machine or at least excessivestrain on the parts which should be prevented.

The objects of the present invention are to secure simple and efficientmeans for automatically regulating and controlling the motive fluid at apredetermined speed of the drill spindle, preferably after maximumhorse-power has been developed by the machine, so that over-speedingand' racing are prevented upon substantial decrease of resistance torotation. I

Pneumatic tools of the type referred to are relatively small, compact,self-contained machines, in order that they may be portable and readilyhandled, and a overnor for accomplishing the objects of this inventionmay be incorporated in the tool in various ways. In the accompanyingdrawings which illustrate the invention, I have shown some of thepreferred ways, but the invention is not to be understood as limited tothe forms of devices shown, as those skilled in the art may deviseequivalent constructions for accomplishing the same purpose, withoutdeparting from the spirit of the invention as defined in the appendedclaims,

In the drawings, Figure l is a side elevation of a pneumatic drillpartly in vertical section, with the cylinder casing and crank coverpartly broken away, only so much of the complete machine being shown aswill serve to illustrate the invention, thus'simplifying the disclosure;

Figure 2 is a detail longitudinal sectional elevation of the rotarydistribution and exhaust valve forming a part of the machine and havingone form, of centrifugal governor applied thereto for throttling theexhaust as a convenient location for the governor;

Figure 3 is an end View of the valve shown in Figure 2 looking at theexhaust end; 75

Figure 4 is a longitudinal. sectional elevation of the. valve with thesection taken ,in a plane at right angles to Figure 25 Figure 5 is adetail longitudinal sectional elevation of a. portion of the same valvehaving a different form of exhaust governor. a

Figure 6 is an end View of Figure 5 showing the governor weights in openposition;

Figure '7 is a view similar to Figure 6 showingthe governor weights inpartially closed position; 1

Figure'8 is a side elevation of a portion of the valve having a modifiedform of governor somewhat similar to that shown in Figure 5 and with adifferent form of spring;

Figure 9 is a longitudinal sectional elevation of Figure 8, I

Figure 10 is an end view of Figure 8, with the end plate removed, and a.Figure 11 is a view similar to Figure 10 showing the Weights inpartially closed position.

Referring to the drawings, the case or cylinder casing A having theremovable crank cover B and the removable gear case or front head Cforms the frame of the machine enclosing and supporting the operatingparts for imparting rotation to a drill bit D or other tool carriedinthe spindle E. The drill bit orother tool is fed forward to its Workby suitable feeding devices the details,

of which are not shown but are adapted to" be manipulated by the manualrotary handle F of any suitable form. The usual point 1m G is shown forengaging an abutment for resisting rearward thrust.

In this instance, and for illustrative purposes, a suitable driven shaftin the form of a crank shaft H is mounted in the ball-bearings J in thecase A beneath the crank cover B and adapted to be actuated by a fluidactuated motor of any suitable type, as for instance a multicylindermotor having 0pposed cylinders, two of the cylinders K and L beingindicated in the drawing at one side of the machine and at an angle tothe axis, the remaining pair not be ng shown since they are in thatportion of the cylinder casing which has been brokenaway. One of thepiston connecting rods 0, in this instance the connecting rod for thecylinder L, is shown suitably connected to the crank P on the crankshaft H with the interpos1- tion of a roller bearing. So much of thedriving mechanism has been shown and described in order to indicate thata form of fluid actuated motor is provided for driving the rotary crankshaft H, from which shaft suitable operative connections are pro videdfor driving the spindle E. In this instance a pinion Q on the crankshaft H meshes with a gear R on the spindle for driving purposes,forming a reduction gearing.

The crank cover B may be provided with a suitable handle S shown brokenaway,

and another opposite handle T also shown broken away, on the case Aconveniently forms the supply inlet for motive fluid to drive the motor.In the present instance, means for automatically distributing motivefluid under pressure to the motor is shown in the form of a hollowrotary valve U adapted to rotate in the sleeve V and provided with thepinion W meshing with the spindle gear B so that the valve is rotatedconstruction is, however, suitable and convenient. The details of thedistribution of motive fluid through the different ports and passagesneed not be further described as they form no part of the presentinvention.

In accordance with my invention means are provided for automaticallyregulating and controlling'the motive fluid at a predetermined speed ofthe spindle after maximum power has been developed by the ma chine andoverspeeding and racing are prevented upon a given decrease ofresistance to rotation. l/Vhile a governor of suitable form can beapplied to. the inlet of the machine, I prefer to provide a governor forthrottling the exhaust to prevent overspeeding and racing. This governorneed not be of the centrifugal form but I have found that a centrifugalgovernor may be simply constructed, requires few parts, is not liable toget out of order and is a preferable form for these and other reasons.\Vhile a centrifugal governor for throttling the exhaust may beconnected to any suitablerotating part of the machine, I prefer to mountthe parts of the governor directly upon the rotary valve U, since thisforms a simple mode of construction and renders the governor readilyaccessible by removing a plug 6 provided for closing that portion of thecase forming the valve casing. Although I have shown but one rotarycontrolling valve in the present machine, the invention is equallyapplicable to a machine having a plurality of valves.

In the form of device shown in Figures 1 to l inclusive, spring arms 0and d which may be formed in one continuous piece are suitably securedwithin the hollow central portion X of the valve U as by means of thepin e and provided with weights f and g at their outer ends. The hollowcentral portion X of the valve is preferably square or rectangular incross section as shown in end view in Figure 3, and the spring arms 0and a. are preferably of flat sheet metal substantially the width of theside of the square hollow portion X of the valve, so that as thegovernor weights 7 and g fly outwardly to the positions indicated indotted lines in Figure 2 the exhaust is throttled and when the springarms 0 and (I bear against the edges of the opening X as indicated inthe dotted position in Figure 2 the exhaust is substantially closed.Adjustable set screws It and j may be set into the valve to bear againstthe spring arms in order to limit the flexibility of said arms.

In the operation of the device so far described, let it be assumed thatthe machine is running at full speed and that a hole is being reamed.When the bit is lifted or withdrawn from the hole, resistance to 1'0-tation is removed, and increase of speed beyond a predetermined amountwill automatically cause the governor weights f and g tofly outwardlyand throttle the exhaust thus preventing over-speeding and racing,

In the modification shown in Figures 5, 6 and 7 circular weights is and0, each open at one side, may be pivoted on the pins and (,1 on the endofthe valve U. These weights as shown have cut-away portions 7 and s soformed with a tubular portion 3 outside of which the circular governorweights 4 and 5 are pivoted on the pins 6 on the flange 7. The weightsshould be free to move on their pivots without binding, and for thispurpose; spacers 8 slightly longer than the thickness of the weights areplaced over the pins,6 and an end plate 9 having'an aperture 10substantially equal in diameter to the bore of the inner tubular portion3 of the body 2, is secured to the pins 6. The heads of the pins may beupset as shown, as a convenient means for holding them in position andsecuring the parts together. The governor arms 11 and 12 move to andfrom each other across the end of the tubular portion 3 of the governorbody and in this instance a semicircular spring 13 lying in the grooves14 in the governor weights, is provided with hooked ends 15 engagingnotches 16 in the weights.

By carrying the tubular governor body 2 out to a point directly beneaththemovable governor arms, 11 and 12, so that said arms move across theend of the tubular body portion 3, for throttling the exhaust, freezingis prevented because the exhaust passes substantially directly toatmosphere.

I claim:

-1. In a portable fluid actuated rotary hand tool, the combination of acrank shaft adapted-to be actuated by a fluid operated motor, a toolspindle adapted to carry aworking tool and connected to be rotated bythe said crank shaft, a rotary valve actuated by the said crank shaftfor automatically distributing and exhausting motive fluid underpressure in the machine, and a centrifugal governor mounted directly onsaid valveand adjustable-to operate at a pro-determined speed of thevalve after maximum power has been developed by the machine forautomati-. cally regulating and throttling the exhaust of motive fluidfrom the machine, whereby over-speeding and racing are prevented uponsubstantial decrease of resistance to rotation of the working tool.

2. In a portable fluid actuated rotary hand tool, the combination of acrank shaft adapted to be actuated bya fluid operated motor, a toolspindle adapted to carry a working tool and connected to be rotated bythe saitr'crank shaft, a rotary valveactuated by the said crank shaftfor automatically distributing and exhausting motive fluid underpressure in the machine, the exhaust passing through the said valve, anda centrifugal governor mounted directly on said valve adjustable tooperate at' a predetermined speed of thevalve after maximum power hasbeen developed by the machine for automatically regulating andthrottling the exhaust of motive fluid from the machine, wherebyoverspeeding and racing are prevented upon substantial decrease ofresistance to rotation of the working tool. v

3. In a portable fluid actuated rotary hand tool the combination of acrank shaft adaptedto be actuated by a fluid operated motor, a toolspindle adapted to carry a working tool and connected to be rotated bythe said crank shaft, a hollow cylindrical rotary valve rotated by thesaid crank shaft for automatically distributing and exhausting motivefluid under pressure in the machine. the exhaust passing through thesaid valve and to atmosphere from the open end of the valve, and acentrifugal governor mounted directly on said valve and controlling theopen end of the valve, sai d governor being adjustable to ,operate at apredetermined speed of the valve after maximum power has been developedby the machine for auto-- n'la tically throttling the exhaust of motivefluid from the machine, whereby over-speed ing and racing are preventedupon substantial decrease of resistance to rotation of the working tool.

4. In a portable fluid actuated rotary hand tool. the combination of afluid operated motor, valve operated thereby for admitting andexhausting motive fluid to and from saidmotor. and means actuated bysaid valve and automatically operable only 'at' -speeds of said motorabove a predetermined minimum to throttle the exhaust of said motivefluid.

5. In a portable fluid actuated rotary hand-tool, the combination of afluid operated motorhaving a valve operated thereby for admitting andexhausting motive fluid to and from sald motor, said valve being hollowto conductthe exhaust fluid,

thereby to conduct exhaust fluid from said motor, and open at one endthrough which the exhaust is discharged, and a member arranged to berotated with said valve and adapted to close said open end upon rotationof the motor above a predetermined speed. V

8. In a portable fluid actuated rotary hand tool, the combination of afluid operated motor, a hollow rotary valve operated thereby to conductexhaust fluid from said motor and open at one end through which theexhaust is discharged, and means including centrifugally operated armsarranged to close said open end upon rotation of said motor above apredetermined speed.

9. In a portable fluid actuated rotary hand tool, the combination of afluid operated motor, a hollow rotary valve operated thereby to conductexhaust fluid from said motor and open at one end to discharge theexhaust, and arms mounted on said valve arranged to swing automaticallyin a direction to close said open end.

10. In a portable fluid actuated rotary hand tool, the combination of afluid operated motor,- a hollow rotary valve operated thereby to conductexhaust fluid from said motor and open at one end to discharge theexhaust, arms mounted on said valve arranged to :swing automatically ina direction to close said open end and weights on saidarmsccentrifu'gally operated upon rotation of said'motor only above apredetermined speed.

12. In a portable fluid actuated rotary hand tool, the combination of afiuid operated motor, a hollow rotary valve operated thereby to conductexhaust fluid from said motor and a governor comprising a tubular bodymounted on said valve, arms pivotally supported by said body, andweights to move said arms across the end of said tubular body uponrotation of said motor above a predetermined speed.

13. In a portable fluid actuated rotary hand tool, the combination of afluid operated motor, a hollow rotary valve operated thereby to conductexhaust fluid from said motor, and a governor comprising a tubular bodymounted on said valve normally providing an unrestricted escape for suchexhaust, arms pivotally mounted on the outside of said tubular body,and'weights to move said arms across the end of said body upon. rotationof said motor above a pre determined speed.

In testimony whereof I have signed this specification.

FREDERICK W. PARSONS.

